Franckes sign, also known as Diamond sign or Reverse prayer sign, refers to a physical examination finding that indicates severe restrictive lung disease. This sign involves the forced adduction and flexion of the fingers, resembling a prayer position with palms facing backwards. The name "Franckes sign" is derived from the German physician, August Franz von Francke, who extensively studied lung pathology. The term "Diamond sign" aptly describes the shape formed by the hands, resembling a diamond. Similarly, "Reverse prayer sign" highlights the reversed or opposite position of the hands when compared to a normal prayer gesture. These synonyms accurately depict this distinctive physical indicator of restricted lung function.